Effectiveness of repetitive transcranial magnetic stimulation in patients with fibromyalgia: a meta-analysis

Even though repetitive transcranial magnetic stimulation (rTMS) has been used for a decade for the treatment of fibromyalgia, evidence of its effectiveness has not been definitely presented. The aim of this study was to investigate whether there is evidence of rTMS being effective in decreasing the severity of pain among patients with fibromyalgia. CENTRAL, MEDLINE, EMBASE, CINAHL, SCOPUS, WEB OF SCIENCE, and relevant references of the identified studies were searched. Randomized controlled studies on adults with fibromyalgia were included. The outcome studied was change in pain severity. Methodological quality was assessed using the scale introduced in the Guidelines for Systematic Reviews in the Cochrane Collaboration Back Review Group. A random-effects meta-analysis was carried out with a test for heterogeneity using the I and pooled estimate as a nonstandardized mean of difference in change in pain severity measures by a numeric rating scale. The search resulted in 791 records, eight relevant, and meta-analyses on seven trials. The risk of bias was considered low for seven studies. Pain severity before and after the last stimulation decreased by -1.2 points on 0-10 numeric rating scale (95% confidence interval: -1.7 to -0.8). Pain severity before and 1 week to 1 month after the last stimulation decreased by -0.7 points (95% confidence interval: -1.0 to -0.3). Both pooled results were below the minimal clinically important difference of 1.5 points. There is moderate evidence that rTMS is not more effective than sham in reducing the severity of pain in fibromyalgia patients, questioning the routine recommendation of this method for fibromyalgia treatment.